<p>I had similar concerns when I entered college gen chem…many of my peers had taken AP chem in junior or senior year of hs, and while I had taken honors chem, it was sophomore year of hs and I had forgotten most of it (I opted for AP bio instead of AP chem my junior year). The professor went through the first 5 chapters of the book as a “review” rather quickly, but it was still enough time to get the hang of things I had forgotten or not learned. I aced the course easily, although I did have to put in the time to study. If you’re not comfortable with the information at all, there might be a course intended to prep students to take gen chem as apumic said, or find a tutor in college. At my school they offer free tutoring by other students or TAs, and oftentimes if you’re struggling the professors will even offer to help out.</p>